An inverse estimation scheme to measure steady-state tool–chip interface temperatures using an infrared camera

A new technique is developed to estimate the average steady-state chip–tool interface temperature during turning. An infrared (IR) video camera attached on the carriage of the lathe measures the transient cooling behavior on the rake surface of an insert after the feed motion is halted. This allows the zero heat flux boundary condition, where the transient Laplace heat conduction problem can be solved numerically to obtain the temporal and spatial temperature distribution. With the experimentally determined transient temperature distribution, the one-dimensional ellipsoidal model is used to estimate the average steady-state chip–tool interface temperature during machining. The results on turning gray cast iron (GCI) and AISI 1045 steels with various coated and uncoated K313 carbide inserts are presented.